Field
The present disclosure relates generally to intelligent electronic devices (IEDs) and, in particular, to intelligent electronic devices with constant calibration capabilities for high accuracy measurements.
Description of the Related Art
Monitoring of electrical energy by consumers and providers of electric power is a fundamental function within any electric power distribution system. Electrical energy may be monitored for purposes of usage, equipment performance and power quality. Electrical parameters that may be monitored include volts, amps, watts, vars, power factor, harmonics, kilowatt hours, kilovar hours and any other power related measurement parameters. Typically, measurement of the voltage and current at a location within the electric power distribution system may be used to determine the electrical parameters for electrical energy flowing through that location.
Devices that perform monitoring of electrical energy may be electromechanical devices, such as, for example, a residential billing meter or may be intelligent electronic devices (“IED”). Intelligent electronic devices typically include some form of a processor. In general, the processor is capable of using the measured voltage and current to derive the measurement parameters. The processor operates based on a software configuration. A typical consumer or supplier of electrical energy may have many intelligent electronic devices installed and operating throughout their operations. IED's may be positioned along the supplier's distribution path or within a customer's internal distribution system. IED's include revenue electric watt-hour meters, protection relays, programmable logic controllers, remote terminal units, fault recorders and other devices used to monitor and/or control electrical power distribution and consumption. IED's are widely available that make use of memory and microprocessors to provide increased versatility and additional functionality. Such functionality includes the ability to communicate with remote computing systems, either via a direct connection, e.g. modem or via a network. IED's also include legacy mechanical or electromechanical devices that have been retrofitted with appropriate hardware and/or software allowing integration with the power management system.
Typically an IED is associated with a particular load or set of loads that are drawing electrical power from the power distribution system. The IED may also be capable of receiving data from or controlling its associated load. Depending on the type of IED and the type of load it may be associated with, the IED implements a power management function that is able to respond to a power management command and/or generate power management data. Power management functions include measuring power consumption, controlling power distribution such as a relay function, monitoring power quality, measuring power parameters such as phasor components, voltage or current, controlling power generation facilities, computing revenue, controlling electrical power flow and load shedding, or combinations thereof.